Centrifugal clutch and switch



Oct. 16, 1934. w. A. CHRYST CENTRIFUGAL CLUTCH AND SWITCH Original Filed July 10, 1928 2 Sheets-Sheet l Oct. 16, 1934. w A CHRYST 1,976,925

CENTRIFUGAL CLUTCH AND SWITCH Original Filed July 10, 1928 2 SheetsSheet 2 Jnwnl'ot Patented Oct. 16, 1934 UNITED STATES CENTRI FUGAL CLUTCH AND SWITCH William A. Chryst, Dayton, Ohio, assignor, by

mesne assignments, to General Motors Corporation, Detroit, Mich,

ware

a corporation of Dela- Original application July 10, 1928, Serial No. 291,629. Divided and this application December 17, 1931, Serial No. 581,638

8 Claims.

This invention relates to centrifugal switches for controlling the circuit of the starting winding of an alternating current motor.

It is one of the objects of the present invention to provide a centrifugal switch of simple and economical construction and one which is readily adapted to be used in combination with a centrifugal clutch by which the rotor of the electric motor is connected with a driving pulley after a certain motor speed has been attained.

This application is a division of my copending application Serial Number 291,629, filed July 10, 1928 and which has eventuated in Patent No. 1,842,820, dated Jan. 26, 1932.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a longitudinal sectional view of a unitary structure embodying the present invention and comprising a centrifugal clutch and centrifugal switch.

Fig. 2 is a view similar to Fig. 1 showing the clutch engaged and the switch open.

Fig. 3 is a side elevation of the switch and is viewed on the plane of the line 3-3 of Fig. 1.

Fig. 4' is a sectional view on the line 4-4 of Fig. 3.

Figs. 5 and 6 are sectional views on the lines 5-5 and 6-6 respectively of Fig. 1.

The unitary power transmitting structure which may be attached to a driving shaft indicated by numeral 20 comprises a flywheel 21 attached by a set serew'22 (see Fig. 6) to the shaft 20, a driving clutch plate 23, a floating driving clutch plate 24, a driven clutch plate 25 carrying friction inserts, 26, and a driving pulley or other transmitting device 27 to which the plate 25 is attached by screws 28. The pulley 27 is provided with a bearing 29 journalled upon the shaft 20. The bearing 29 is formed preferably of a porous metallic structure capable of absorbing lubricant which is fed to it from a small reservoir 30 provided by that portion of the hub of pulley 27 which extends beyond the end of the shaft 20. One wall of the reservoir 30 is provided by plug 31 of felt or other flbrous oil absorbing material and the plug 31 is retained in position by a metal plug 32 through which oil may be squirted through a hole 33.

The plate 23 and a paper gasket 35 are attached by screws 36 to the flywheel 21. The

driving plate 24 is supported for rotary and axial movement by the flywheel 21. To accomplish this a plate 37 is attached to the flywheel 21 by rivets 37a and is provided-with apertures 38 each surrounded by an annular flange 39 which provides a guide bearing for a stud 40 attached at one end to the plate 24. There are preferably three studs 40 for supporting the plate 24 for endwise. movement. The studs 40 are each attached at their other ends to a plate 41 having a central aperture 42 for receiving the shaft 20. Springs 43 each surrounding a stud 40 are confined in an initial state of compression between the plate 41 and the plate 37 and yieldingly urge the plate 24 away from the plate 23 in order that the driven plate 25 will be normally disconnected from the driving plates 23 and 24. The speed responsive means for moving the plate 24 toward the plate 23 in opposition to the action of the springs 43 includes a plurality of balls 44 each of which is guided for radial movement by the walls of a pocket 45. Each pocket 45 is defined. by a portion of the plate 24, by a pair of parallel ears 46 integral with the plate 37 and by a surface 47 provided by the web 48 of the flywheel 21, said surface 47 being oblique to the plane of the plate 24. It is therefore apparent that as the speed of the shaft 20 increases, the balls 44 will move radially outward and in an oblique path due to 85 engagement with the oblique surfaces 47. Therefore, the plate 24 will be moved toward thenright in the drawings and will be wedged against the friction inserts 26 of the plate 25 and will cause them to be frictionally engaged also with the plate 23 as shown in Fig. 2. Thus, above a certain predetermined speed of the shaft 20, the shaft will be connected with the pulley 27 through the friction clutch provided by the plates 23 and 24 and inserts 26. As the speed of the shaft decreases, the springs 43 will be increasingly effective to move the plate 24 out of frictional engagement with the inserts 26 and to cause the plate to force the balls 44 against the oblique surfaces 47 so that the balls will finally be returned to normal position shown-in Fig. 1. Thus the friction clutch will be disengaged below a certain speed of the shaft 20. There is clearance between the pulley 2! and the hub of the fly-wheel 21 so that the inserts 26 may move endwise away from the plate 23.

The centrifugal means for controlling the clutch operates also to control an electric circuit for an electric motor which drives the shaft 110 20. As shown, this motor may be an induction motor having a squirrel cage armature 50 carried by the shaft 20 which is journalled in a plurality of bearings, one of which is shown at 51 supported by the frame 52 of the motor. The motor includes a field frame 53 carrying stator pole pieces 54 and stator'windings 55. The induction motor is provided with a starter circuit which is' maintained normally closed by a pair of switch contacts 60 and 61 carried by leaf spring conductors 62 and 63 respectively connected with terminal plates 64 and 65 respectively. These parts are insulatingly supported by the motor end frame 52, with the parts 62 and 64 in engagement and parts 63 and 65 in engagement as shown in Figs. 3 and 4. The leaf spring 63 is normally biased so as to maintain the contact 61 separated from the contact 60. When the motor is at rest the contact 61 is held in engagement with the contact 60 due to the action of the springs 43 which press the plate 41 against two projections 66 extending from a plate 67 which is pivoted upon a screw 68 so as to swing laterally relative to the motor end frame 52. The plate 67 is provided with a central hole 63 for receiving the shaft 20, the shaft preventing the plate 6''! from rotating about the screw 68. The free end of the plate 6'? carries a stud '70 which bears against spring conductor 63 and maintains the contact 61 in engagement with the contact 60.

When the balls 44 move outwardly to engage the clutch members, the plate 41 is moved toward the right from the position shown in Fig. 1 to that shown in Fig. 2, in order to permit the the plate 67 to swing away from the motor frame 52 and to permit the spring conductor 63 to separate the contact 61 from the contact 60.

The centrifugal clutch and switch mechanism may readily be disassembled. After removing the set screw 22 the unitary assembly of flywheel, pulley, centrifugalclutch and centrifugal switch controller 41 may be removed from the shaft 20. After removing the screw 68, the plate 67 may be removed from the motor. After removing the screws which attach the switch members to the frame and after disconnecting the wires 81 and 82 from the switch members by removing the screws 83, the switch contacts and terminals may be removed from the motor.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A combined centrifugal clutch and switch comprising coaxially rotatable driving and driven members; clutch plates connected respectively with said members; a switch controller movable axially with respect to thedriving member; and a common speed responsive device for moving the controller axially and one of the clutch plates axially into engagement with the other.

2. A combined centrifugal clutch and switch comprising coaxially rotatable driving and driven members; clutch plates connected respectively with said members; a switch controller movable axially with respect to the driving member; weight members carried by the driving member and guided thereby for lateral movement, and a part movable axially of the driving member in response to lateral movement of the weight members and connected with the switch controller and engageable with one of said clutch plates.

3. A combined centrifugal clutch and switch comprising coaxially rotatable driving and driven members; clutch end plates connected with the driving member, one of them being axially movable; an intermediate plate located between the end plates and connected with the driven memher; a switch controller movable axially with respect to the driving member and attached to the axially movable driving plate; and speed responsive means operated by the driving member for causing the axially movable plate to operate the controller and to bear against the intermediate plate.

4. A combined centrifugal clutch and switch comprising rotatable driving and driven members; frictionally engageable clutch parts connected respectively with said members; a speed responsive device for moving one of said parts axially into engagement with the other; and a switch controller movable axially in response to movement of the same speed responsive means.

5. A combined centrifugal clutch and switch comprising rotatable driving and driven members; frictionally engageable clutch parts connected respectively with said members; an axially movable switch controller actuated by one of said parts; a common resilient member urging said controller and one of said parts to a normal position; and weight members carried by the driving member for actuating the controller and effecting engagement of said parts.

6. A starting mechanism for a motor having a rotor drivingly mounted on a rotatably supported shaft comprising a first clutch member secured to the shaft and rotatable therewith; a part to be driven by the shaft; a movable clutch member; centrifugal means for actuating the movable clutch member; an intermediate clutch member connected with said part and located between the first clutch member and movable clutch member, said intermediate clutch member being gripped therebetween when a predetermined rotor speed is reached; a switch controller actu- 12f ated by' one of said clutch members; and common resilient means for urging the movable clutch member and switch controller toward a normal position.

7. In a starting mechanism for a motor having a rotor drivingly connected to a rotatably mount- 'ed shaft, the combination comprising, a driven member; a first clutch part secured to the driven member for transmitting the driving force thereto; an axially movable clutch part for effecting a driving engagement between said first clutch part and the rotor; a switch controller connected to and actuated by the movable clutch part;

.and means including a common spring for urging the movable clutch part and switch controlle toward their normal position.

8.1 combined centrifugal clutch and switch comprising coaxially rotating and driven members, clutch end plates connected with the driving member, one of them being axially movable, an intermediate plate located between the end plates and connected with the driven member, a switch controller movableaxially with respect to the driving member and connected to the axially movable driving plate, and speed responsive means operated by the driving member for causing the axially movable plate to operate the contiioltlgr and to bear against the intermediate p a WILLIAM'A. CHRYST. 

